《地形模型的三维可视化》程序设计

《地形模型的三维可视化》程序设计

一、题目

请用OpenGL图形库，编制程序实现地形模型的三维可视化，并进行地形模型的纹理设置，并可以通过键盘进行交互操作（移动和旋转）。

（注：给定的地形模型数据是已经建好的不规则三角网。）

二、提交资料

1．程序的详细步骤和所有相关数据；

步骤：①录入三角形数据

②获得地形的范围

③绘制三角网

④设置纹理坐标

⑤计算参考点的位置

⑥移动

相关数据文件：数据文件DHS.dat

三角网文件DHS.tri

图片文件TERRAIN.BMP

2. 程序清单(包括程序说明)；

#include "stdafx.h"

#include

#include

#include

#include

#include

#include

void CALLBACK elbowAdd (void);

void CALLBACK elbowSubtract (void);

void CALLBACK shoulderAdd (void);

void CALLBACK shoulderSubtract (void);

//点结构定义

typedef struct

{

long id;

double x;

double y;

}POINTXYZ;

//三角形结构定义

typedef struct

{

long id; //三角形号

long p[3]; //三角形三个顶点的序号

long xl[3]; //拓扑关系

}TRIANGLE;

//顶点变量

POINTXYZ *pPt;

//三角形变量

TRIANGLE *pTri;

//顶点总数

int iTotalNum;

//三角形总数

int iTotalTriNum;

//外围结构

typedef struct vrtagBOX

{

double minx;

double miny;

double minz;

double maxx;

double maxy;

double maxz;

}vrBOX;

//外围结构

vrBOX _box;

unsigned int m_nID; //存储纹理的索引号

int m_nWidth; //纹理图片的宽度

int m_nHeight; //纹理图片的高度

float (*_ptexture)[2]; //存储三角网的纹理数据

//视点参考点的偏移量

double lookx, looky, lookz;

//移动的速度

float _speed;

//垂直方向视点和所要看实体的间的距离

//视点的位置

double _eyeposition[3];

//参考点的位置

double _referencepoint[3];

//鼠标位移与象素之比的分母，即象素数

int _Pixels;

//设置纹理坐标

void SetTextureCoord();

//读取纹理数据

bool LoadTriangleBMP( LPSTR szFileNameD);

//向前移动

void Move(bool is_forward);

//获得鼠标在x，y方向的相对位移量

bool Rotate(int dx, int dy);

//计算视点与参考点的位置

void _CalcuEyePositionAndReferencePoint(int type,float amount);

void myinit(void);

//读取点坐标、三角形数据

void ReadData();

void Render();

//获得外围

void SetBOX();

void CALLBACK myReshape(GLsizei w, GLsizei h);

void CALLBACK display(void);

//读取纹理数据

bool LoadTriangleBMP(char* szFileName)

{

AUX_RGBImageRec *pBitmap = NULL;

if(!szFileName) return false;

//装载数据并存储

pBitmap = auxDIBImageLoad(szFileName);

if(pBitmap == NULL) return false;

glGenTextures(1, &m_nID);

// 绑定纹理到纹理数组，并进行初始化。

glBindTexture(GL_TEXTURE_2D, m_nID);

//控制纹理，映射到片元(fragment)时怎样对待纹理。

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

//定义二维纹理

glTexImage2D(GL_TEXTURE_2D, 0, 3, pBitmap->sizeX, pBitmap->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, pBitmap->data);

m_nWidth = pBitmap->sizeX;

m_nHeight = pBitmap->sizeY;

if (pBitmap) delete pBitmap;

return true;

}

int main(int argc, char* argv[])

{

/* 设置双缓存和RGBA颜色模式*/

auxInitDisplayMode (AUX_DOUBLE|AUX_RGBA);

auxInitPosition (0, 0, 1600, 800);

auxInitWindow ("作业");

myinit();

auxReshapeFunc (myReshape);

auxKeyFunc (AUX_LEFT, shoulderSubtract);

auxKeyFunc (AUX_RIGHT, shoulderAdd);

auxKeyFunc (AUX_UP, elbowAdd);

auxKeyFunc (AUX_DOWN, elbowSubtract);

auxMainLoop(display);

return 0;

}

void CALLBACK elbowAdd (void)

{

Move(true);

}

void CALLBACK elbowSubtract (void)

{

Move(false);

}

void CALLBACK shoulderAdd (void)

{

Rotate(50,0);

}

void CALLBACK shoulderSubtract (void)

{

Rotate(-50,0);

}

//读取点坐标、三角形数据

void ReadData()

{

ifstream ifile("f:\\qq\\DHS.dat");

ifile >> iTotalNum;

pPt =new POINTXYZ[iTotalNum];

//循环读入定顶点坐标数据;

for (int i=0;i

{

ifile >>pPt[i].id >> pPt[i].x >>pPt[i].y >> pPt[i].z;

}

ifile.close();

ifstream ifile2("f:\\qq\\DHS.tri");

ifile2 >> iTotalTriNum;

pTri =new TRIANGLE[iTotalTriNum];

//循环读入定顶点坐标数据;

for ( i=0;i

{

ifile2 >>pTri[i].id >> pTri[i].p[0] >>pTri[i].p[1] >> pTri[i].p[2]; }

ifile2.close();

SetBOX();

}

//功能：获得地形的范围

void SetBOX()

{

_box.minx = 9900000;

_box.miny = 9900000;

_box.minz = 9900000;

_box.maxx = -9900000;

_box.maxy = -9900000;

_box.maxz = -9900000;

//对所有的顶点循环

for (int i = 0; i < iTotalNum; i++)

{

if(_box.minx > pPt[i].x) _box.minx = pPt[i].x;

if(_box.miny > pPt[i].y) _box.miny = pPt[i].y;

if(_box.minz > pPt[i].z) _box.minz = pPt[i].z;

if(_box.maxx < pPt[i].x) _box.maxx = pPt[i].x;

if(_box.maxz < pPt[i].z) _box.maxz = pPt[i].z;

}

}

void myinit(void)

{

//读取点坐标、三角形数据

ReadData();

char *_bmpfilename; //纹理图片的文件名

_bmpfilename="f:\\qq\\TERRAIN.BMP"; //terrain.bmp"; //suban_1.bmp"; //读取纹理数据

LoadTriangleBMP(_bmpfilename);

//计算纹理坐标

SetTextureCoord();

//设置视点的一些初始参数

lookx = 5.0f;

looky = 0.0f;

lookz = 0.0f;

_Pixels= 3000;

_height=2.50;

_speed= 5.0f;

_eyeposition[0] = _box.minx -300;

_eyeposition[1] = _box.miny -300;

_eyeposition[2] = _box.maxz+50;

_referencepoint[0] = _box.maxx;

_referencepoint[1] = _box.maxy;

_referencepoint[2] = _box.minz;

}

void CALLBACK myReshape(GLsizei w, GLsizei h)

{

glViewport(0, 0, w, h);

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 90000.0);

glMatrixMode(GL_MODELVIEW);

glLoadIdentity();

}

{

glClearColor(1.0,1.0,1.0,0.0);

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glPushMatrix();

//投影变换

gluLookAt(_eyeposition[0] , _eyeposition[1] , _eyeposition[2],

_referencepoint[0], _referencepoint[1] , _referencepoint[2], 0,0,1);

glPushMatrix();

glTranslated (_box.maxx+300 ,_box.maxy+100 , _box.maxz+300);

glColor3f (1.0, 0.0, 0.0);

auxSolidSphere (50.0);

glPopMatrix ();

GLfloat mat_ambient[]= { 1.0, 1.0, 1.0, 1.0 };

GLfloat mat_diffuse[]= { 1.0, 1.0, 1.0, 1.0 };

GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };

GLfloat mat_shininess[] = { 50.0 };

GLfloat light0_diffuse[]= { 1.0, 1.0, 1.0, 1.0};

//定义光源的位置

GLfloat light0_position[] = { _box.maxx,_box.maxy, _box.maxz-800, 1.0 };

GLfloat light1_ambient[]= { 1.0, 0.0,0.0, 1.0 };

GLfloat light1_diffuse[]= { 1.0, 0.0, 0.0, 1.0 };

GLfloat light1_specular[] = { 1.0, 0.0, 0.0, 1.0 };

GLfloat light1_position[] = { (_box.minx +_box.maxx)/2.0 ,(_box.miny +_box.maxy)/2.0 , _box.maxz+500, 1.0 };

GLfloat spot_direction[] = { 0.0, 0.0, -1.0 };

glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);

glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);

glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);

glMaterialfv(GL_FRONT, GL_SHININESS,mat_shininess);

glLightfv(GL_LIGHT0, GL_AMBIENT, light0_diffuse);

glLightfv(GL_LIGHT0, GL_DIFFUSE, light0_diffuse);

glLightfv(GL_LIGHT0, GL_POSITION,light0_position);

glLightfv(GL_LIGHT1, GL_AMBIENT, light1_ambient);

glLightfv(GL_LIGHT1, GL_DIFFUSE, light1_diffuse);

glLightfv(GL_LIGHT1, GL_SPECULAR,light1_specular);

glLightfv(GL_LIGHT1, GL_POSITION,light1_position);

glLightf (GL_LIGHT1, GL_SPOT_CUTOFF, 10.0);

glLightfv(GL_LIGHT1, GL_SPOT_DIRECTION,spot_direction);

glEnable(GL_LIGHT0);

glDepthFunc(GL_LESS);

glEnable(GL_DEPTH_TEST);

//启动光照

glEnable(GL_LIGHTING);

//绘制地面模型

Render();

glDisable(GL_LIGHTING);

glPopMatrix();

glFlush();

auxSwapBuffers();

}

//功能：绘制三角网

void Render()

{

glBindTexture(GL_TEXTURE_2D, m_nID);

glEnable(GL_TEXTURE_2D);

//画三角形线面

glBegin(GL_POLYGON); //GL_LINE_LOOP);//

for( int i = 0; i < iTotalTriNum; i++)

{

glTexCoord2f(_ptexture[pTri[i].p[0]][0], _ptexture[pTri[i].p[0]][1] );

glVertex3f(pPt[pTri[i].p[0]].x, pPt[pTri[i].p[0]].y, pPt[pTri[i].p[0]].z);

glTexCoord2f(_ptexture[pTri[i].p[1]][0], _ptexture[pTri[i].p[1]][1] );

glVertex3f(pPt[pTri[i].p[1]].x, pPt[pTri[i].p[1]].y, pPt[pTri[i].p[1]].z);

glTexCoord2f(_ptexture[pTri[i].p[2]][0], _ptexture[pTri[i].p[2]][1] );

glVertex3f(pPt[pTri[i].p[2]].x, pPt[pTri[i].p[2]].y, pPt[pTri[i].p[2]].z); }

glEnd();

glDisable(GL_TEXTURE_2D);

}

//设置纹理坐标

void SetTextureCoord()

{

_ptexture = new float[iTotalNum][2];

float _min_max = fabs(_box.maxx -_box.minx);

float _min_maxy = fabs(_box.maxy-_box.miny);

for (int i = 0; i < iTotalNum; i++)

{

_ptexture[i][0] = (pPt[i].x-_box.minx)/_min_max;

}

//计算视点的位置和参考点的位置

void _CalcuEyePositionAndReferencePoint(int type,float amount) {

float a;

double _h;

switch(type)

{

//向前移动就执行这步

case 1:

_eyeposition[0] += lookx * amount;

_eyeposition[1] += looky * amount;

break;

//水平面内旋转就执行这步

case 2:

lookx = lookx*cos(amount) + looky*sin(amount);

looky = looky*cos(amount) - lookx*sin(amount);

a = 1/sqrt(lookx*lookx + looky*looky);

lookx *= a;

looky *= a;

break;

}

//计算参考点的位置

_referencepoint[0] = _eyeposition[0] + lookx;

_referencepoint[1] = _eyeposition[1] + looky;

_referencepoint[2] = _eyeposition[2] + lookz;

}

//向前移动

void Move(bool is_forward)

{

//使视点向前移动

if(is_forward)

{

_CalcuEyePositionAndReferencePoint(1, _speed);

}

else

{

_CalcuEyePositionAndReferencePoint(1, - _speed);

//获得鼠标在x，y方向的相对位移量

bool Rotate(int dx, int dy)

{

//调用_CalcuEyePositionAndReferencePoint()函数完成旋转操作_CalcuEyePositionAndReferencePoint(2, ((float)dx/ _Pixels));

return true;

}

3．程序运行结果。